Simpler and lower tech than lasers . . . from Clark Bremer . . . we have unbreakable mirrors with a hole in the middle.
Sounds improbable, but they work flawlessly to guide your drill in remaining perpendicular to the timber surface.
Cheap, too. http://tfguild.stores.yahoo.net/midrgu.html
Cordless! Y2K Compliant! Energy Star Compliant! Probably Free Range, Organic and Equal Exchange, too.